Diagnostic difficulties in four cases of massive bleeding per rectum.
D000293:Adolescent; D000328:Adult; D002429:Cecal Diseases / Q000175:diagnosis; D002648:Child; D005260:Female; D005767:Gastrointestinal Diseases / Q000175:diagnosis*; D006471:Gastrointestinal Hemorrhage / Q000175:diagnosis*; D006484:Hemorrhoids / Q000175:diagnosis; D006801:Humans; D008297:Male; D008467:Meckel Diverticulum / Q000175:diagnosis; D008551:Melena; D012007:Rectum; D013057:Spectrum Analysis; D014456:Ulcer